Design of new efficient drug delivery systems for proteins is one of the major themes of modern biotechnology and biopharmaceutical industry. We found that cross-linked enzyme crystals (CLECs) show remarkable stability at various pHs, on storage, against proteolysis and organic solvents. These properties make them ideal for treatment against biofilm formation on medical devices /implants such as urethral catheters, ureteric and prostatic stents, penile and testicular implants, artificial urinary sphincters, prostheses for hip and knee replacements, shunts for hydrocephalus, vascular grafts, heart valves, vascular access devices, voice prostheses, etc. In addition, the CLECS can be used for the prevention of blood clot formation, for example, in venous catheters. The CLEC agent will be used to coat the medical devices for the prevention of formation of bacterial biofilms on these devices as well as the prevention of blood clots. The biofilms form on the above medical devices by colonization of bacteria embedded in a matrix, which become resistant to commonly used antibiotics. In this Phase I study, we propose to develop two prototypes of CLECs of enzyme - Serratiopeptidase and Streptokinase for prevention of biofilms by Pseudomonas aeruginosa and Staphylococcus aureus microorganisms. The coating will prevent the adherence of these bacteria to medical devices. Currently, there are more than 850,000 case infections associated with aid devices annually in the United States. These may be associated with as many as 100,000 deaths per year. The CLECs of Serratiopeptidase and Streptokinase have enormous commercial potential over the currently available treatment for the prevention of contamination of medical devices by minimizing the need for replacement once they are implanted. The CLECs of Serratiopeptidase and Streptokinase will also be important in preventing biofilm-related infections which are resistant to commercially available antibiotics.